An aptasensor based on the fluorescence resonance energy transfer of nitrogen-doped carbon quantum dots and graphene oxide to detect fipronil in eggs

Fipronil, as an excellent insecticide, is widely used around the world, but its residues in agricultural products and the environment cause a series of health and ecological risks. In this study, a novel aptamer sensor for the sensitive, selective, and quantitative detection of fipronil in eggs was prepared using nitrogen-doped carbon quantum dots (NCQDs) modified by fipronil aptamer. It is based on the adsorption of apt-NCQDs on the surface of graphene oxide (GO) through π-stacking and hydrophobic interactions, and quenching the fluorescence of apt-NCQDs through the fluorescence resonance energy transfer between NCQDs and GO. In the presence of fipronil, apt-NCQDs were desorbed from GO and the fluorescence resonance energy transfer (FRET) process was inhibited to recover the fluorescence. Under the optimized conditions, the linear range of fipronil was 10–60 nM, R2 = 0.9907, and the LOD was 3.58 nM, which showed good selectivity and sensitivity to fipronil. In addition, the recovery of this method for detection in egg samples ranged 89–104% with an RSD < 8%, which indicates that this method has good prospects for practical application.